Vortex Characteristics of Turbulent Jets in Crossflow

By performing large eddy simulation (LES) on turbulent jet in crossflow with a cone-shaped hole, this paper simulated the unsteady development process of-vortices on different sections at the blowing rate M=1.0, and the vortex structures mechanisms were analyzed. Simulation results showed that: there exist the positive and negative vortices in the centreplane, which the varying period of vortex is 0.024 s; the two wings of the horseshoe vortices in the vertical profiles are shed off new vortices alternately and periodicly, while the period of the horseshoe vortex is 0.032s. The counter-rotating vortex pair (CVP) plays an important effect on the flowing field, where 1<X/D<2, CVP decays along the streamwise gradually, where X/D>4.0, CVP is vanishing, then this causes the energy exchanging quickly near the wall surface. CVP is not symmetry and the positive and negative vortices are mixed, as a result of the pressure gradients not being equal between the upstream and downstream.